Evaluation of interface traps inside the conduction band of InAs-on-insulator nMOSFET by self-consistent Hall-QSCV method

摘要

Interface trap density (D_(it)) inside the conduction band of (111)-oriented InAs-on-insulator (InAs-OI) n-channel metal-oxide-semiconductor field-effect-transistor (nMOSFET) was experimentally evaluated by developing a method through a combination of a Hall measurement and quasi-static split C-V (Hall-QSCV). The surface potential and D_(it) of the InAs-OI nMOSFET were self-consistently calculated by numerically solving the Schrodinger-Poisson equation. The energy distributions of D_(it) were found to be almost independent of the ultra-thin-body channel thickness and the quantization energy, indicating the validity of the proposed Hall-QSCV evaluation. The energy position of the D_(it) minimum is in good agreement with the theoretically predicted position of the charge neutrality level, which locates deeply inside the conduction band of InAs. The experimental maximum surface electron density N_(smax) at the InAs MOS interface, limited by Fermi level pinning, is 1.2 × 10~(13) cm~(-2), which is 2-3 times higher than N_(smax) at the In_(0.53)Ga_(0.47)As MOS interfaces, owing to the lower D_(it) inside the InAs conduction band.